The lichen genus Chrysothrix Mont, is shown to comprise four species: C. candelaris (L.) Laundon comb, nov., C. chlorina (Ach.) Laundon comb, nov., C. chrysophthalma (P. James) P. James & Laundon comb, nov., and C. pavonii (Fr.) Laundon comb. nov. (C. noli-tangere (Mont.) Mont.). The genera Pulveraria Ach. and Temnospora Massal. are placed in the synonymy of Chrysothrix nom. cons., and all bright yellow, leprose, sterile lichens with pulvinic acid derivatives, formerly included in Lepraria and Crocynia, are referred to the genus. Chrysothrix oceanica Rasanen is excluded; it probably belongs to Caloplaca. A key to and detailed accounts of the recognized species are included. There are three chemotypes of Chrysothrix candelaris, one of which is probably of hybrid origin.